Filter cleaning apparatus



Dec. 12, 1950 G. H. VOKES 2,533,644

FILTER CLEANING APPARATUS Filed Oct. 11, 1949 Patented Dec. 12, 1950FILTER CLEANING APPARATUS Gordon Heatherton Vokes, Guildford, England,assignor to Vokes Limited, Guildford, England Application October 11,1949, Serial No. 120,769 In Great Britain October 18, 1948 1 Claim.

There are well-known filtering installations in which bays or sectionsof filtering units are agitated and in some cases a reverse fiowsimultaneously passed through the filterin material to removeaccumulated material from the dirty side. For example, there isdescribed in co-pending specification No. 57,270 such an arrangement inwhich air already cleaned by other sections is periodically passed inthe reverse direction through a section undergoing cleaning and agi- 1tators are simultaneously oscillated inside suitably mounted bags orpockets of filtering material.

The present invention is designed to provide more efficient agitationthan will normally be obtained by a system of rigid or spring mountedrappers oscillated by means of a simple crank arrangement, bysubstituting a system in which rappers are spring actuated (e. g. uponmovement over centre by an oscillating member). The rappers may bechecked, so that the resilience of parts carrying what may be regardedas the heads of the rappers and the momentum of the latter produce asharp blow and an instant recoil.

In the specification referred to slotted or equivalent bars are used totransmit the motion from an oscillating shaft to the several tiers ofunits in a bay or section undergoing cleaning.

As illustrated in a typical form by the accompanying drawings,oscillating (used for convenience hereinafter to include reciprocating)actuating members cause toggle members to pass their dead centrepositions alternately from opposite sides, so that the rapping iseffected by the sharp movement due to a toggle spring becoming operativeon alternate sides of the dead centre position.

In the drawings- Fig. 1 is an elevation,

Fig. 2 is a fragmentary plan, and

Fig. 3 a plan of mechanism for producing oscillation of the actuatinmembers.

As illustrated, a vertical shaft A is caused to oscillate by a cam Bmounted on a rotating shaft 0 suitably driven. The cam B engages aroller D pivotally mounted on a lever E firmly fixed to the verticalshaft A. The roller D is suitably maintained in contact with the cam B,as indicated by the spring loaded plunger F carrying a pin Fl working ina slotted hole in lever E, all as shown in Fig. 3. Obviously any otherconventional means may be used to obtain the desired oscillatory orreciprocating movement.

To the oscillating shaft A there is firmly fixed a lever arm G carryingone end of a tension spring H, the other end of which is attached to thetoggle lever J carried from a fixed pivot at Jl. As the lever arm Goscillates, the toggle lever J will be caused to move sharplyalternately to one side and the other.

This movement is transmitted to the heaters by a cross-bar K providedwith a pin Kl working in a slotted hole in the toggle lever J. The bar Kis pivotally connected to cranks L carried by the beater rods M in theforaminated filter bag frame 0. Beater arms N are carried by the beaterrods and are thus moved sharply in alternate directions by the action ofthe toggle spring J and strike the bag frames.

In order to accentuate the suddenness of the blow, the beater arm N ismade of spring steel or other resilient medium, and is caused to arrestits motion by means of stops P secured firmly to the sdies of theforaminated bag frames, allowing the momentum of the head and itsresilient mounting to produce the desired sharp blow and instant recoil.

The movements of rappers in alternate units (or small groups of units)may be balanced to avoid excessive vibration of the whole by causingsimultaneous beater movement clockwise in one bag and anti-clockwise inthe adjacent bags, for example by engaging alternate cranks respectivelyabove and below the pivotal axis.

I claim:

In a filtering installation having a plurality of filter bags in side byside relationship and oscillatable rapping means within each of saidbags, a single mechanism adapted to actuate the oscillatable rappingmeans within each bag and comprising a plurality of cranks one at theend of each bag operatively connected with the rapping means within thesaid bag, a single bar pivotally connected with each of said cranks, atoggle lever carriedfrom a fixed pivot and connected by a slottedconnection with the said bar, a rotary shaft, an oscillating shaftdriven from the said rotary shaft, an arm mounted on the saidoscillating shaft, and a tension spring connecting the said arm to apoint on the said toggle lever, whereby the spring action from the saidspring is distributed over the said rapping means without otheroperative contact between them.

GORDON IEATHERTON VOKES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 870,830 Lechtenberg Nov. 12, 19071,303,008 Anderson May 6, 1919 1,356,086 Plaisted Oct. 19, 19202,196,839 Seng Apr. 9, 1940

